FRET Between Riboflavin and 9-Anthraldehyde Based Fluorescent Organic Nanoparticles Possessing Antibacterial Activity

The aqueous suspension of fluorescent nanoparticles were prepared by using 9-anthradehdye derivative (AH). The nanoparticles (AHNPs) were characterized using DLS-zeta sizer and SEM techniques. The photo physical properties of nanoparticles and precursor were measured and compared using UV-absorption spectroscopy, fluorescence spectroscopy and fluorescence lifetime studies. The significant overlap between fluorescence spectrum of AHNPs and excitation spectrum of Riboflavin (RF) led us to explore Fluorescence Resonance Energy Transfer (FRET) studies between AHNPs and RF in aqueous medium. The mechanism of FRET from AHNPs to RF discussed on spectral observations, thermodynamic parameters and changes produces in fluorescence lifetime in absence and presence of different concentrations of RF to AHNPs. The limit of detection for RF (0.071 A mu M) is considerably low compared with reported methods. Thus, we explore AHNPs as novel nano probe for quantitative determination of RF in pharmaceutical samples based on FRET study. In addition with this, AHNPs has excellent antibacterial activity than the bulk material for two different bacteria culture viz. E. coli and Bacillus sps.